Scalar Fields Coupled to Four-Dimensional Lattice Gravity

Abstract

I discuss some results we have obtained recently in a lattice model for quantized gravity coupled to scalar matter in four dimensions. We have looked at how the continuous phase transition separating the smooth from the rough phase of gravity is influenced by the presence of the scalar field. We find that close to the critical point, where the average curvature approaches zero, the effects of the scalar field are small and the coupling of matter to gravity seems to be weak. The nature of the phase diagram and the values for the critical exponents would suggest that gravitational interactions increase with distance.